understanding hue and saturation

I shoot a lot of flowers and I want to understand hue and saturation so I can give them some punch. Can anyone point me to a primer on the subject? I've played around with this in Photoshop but I really want to understand what I'm doing instead of just winging it.

Levels and curves are what I use for contrast, color correction. I've always felt that when I start changing the hue in pictures that it looks fake unless you're sampling colors from another similarly lit pic.

While I started out using the curves in PS for some contrast corrections I have turned to the levels now, liking them more because they give you the histogramme of the picture. So you can see at once whether your pic lacks in highlights or dark element, of if you've got a considerable lack of midtones. So you can add some of either or push the middle button so you increase some of the midtones ... and you see what you are doing right away. Sometimes it is only a matter of tiniest adjustments to make the colours pop out more. I hardly ever even touch the "Saturation" level any more.

The histrogram shows where the light is distributed in the pic. The far left of the graph is pure black and the far right is pure white. Most pics won't have an even distribution of points on that curve and it'll be skewed one way or the other. Regardless... if your pic doesn't have a lot of data (the graph is low with data close to they Y axis) it's telling you that the pic doesn't have much that's white / black. When you move those sliders in you're telling it that what points it considered near white... you want it to now consider pure white. When you do that with both the black and white sliders you'll get a better tonal range and more contrast.

You can then use the grey slider to adjust midtones but I've found those adjments are usually more subtle than the black and white.